Hi,
you might wana try Synodontis multipuntatus, i'm pretty sure i saw them at tiong bahru market , the shop next to wuhu.
they are very good vacuum cleaners compared to plecos.
S. multipuntatus is a tanganyikan catfish. If you insist on getting a pleco then i'd recommand bristlenose (easily gotten from petmart or maybe gans) and the royal pleco. these are two plecos that will survive in an african tank and proven to be useful when there's a brown algae problem. However my multipuntatus do eat brown algae too as what i've observed.
A picture of S. Multipuntatus can be found here
http://www.petfrd.com/db/details.php?image_id=180
Hope i was of some help.
Cheers!
Bookmarks